"""CSSVariablesDeclaration

http://disruptive-innovations.com/zoo/cssvariables/#mozTocId496530

"""

__all__ = ['CSSVariablesDeclaration']

import itertools

import cssutils

from cssutils.helper import normalize

from cssutils.prodparser import PreDef, Prod, ProdParser, Sequence

from .value import PropertyValue

class CSSVariablesDeclaration(cssutils.util._NewBase):

"""The CSSVariablesDeclaration interface represents a single block of

variable declarations.

"""

def __init__(self, cssText='', parentRule=None, readonly=False):

"""

:param cssText:

Shortcut, sets CSSVariablesDeclaration.cssText

:param parentRule:

The CSS rule that contains this declaration block or

None if this CSSVariablesDeclaration is not attached to a CSSRule.

:param readonly:

defaults to False

Format::

variableset

: vardeclaration [ ';' S* vardeclaration ]* S*

;

vardeclaration

: varname ':' S* term

;

varname

: IDENT S*

;

"""

super().__init__()

self._parentRule = parentRule

self._vars = {}

if cssText:

self.cssText = cssText

self._readonly = readonly

def __repr__(self):

return f"cssutils.css.{self.__class__.__name__}(cssText={self.cssText!r})"

def __str__(self):

return f"<cssutils.css.{self.__class__.__name__} object length={self.length!r} at 0x{id(self):x}>"

def __contains__(self, variableName):

"""Check if a variable is in variable declaration block.

:param variableName:

a string

"""

return normalize(variableName) in list(self.keys())

def __getitem__(self, variableName):

"""Retrieve the value of variable ``variableName`` from this

declaration.

"""

return self.getVariableValue(variableName)

def __setitem__(self, variableName, value):

self.setVariable(variableName, value)

def __delitem__(self, variableName):

return self.removeVariable(variableName)

def __iter__(self):

"""Iterator of names of set variables."""

yield from list(self.keys())

def keys(self):

"""Analoguous to standard dict returns variable names which are set in

this declaration."""

return list(self._vars.keys())

def _getCssText(self):

"""Return serialized property cssText."""

return cssutils.ser.do_css_CSSVariablesDeclaration(self)

def _setCssText(self, cssText):

"""Setting this attribute will result in the parsing of the new value

and resetting of all the properties in the declaration block

including the removal or addition of properties.

:exceptions:

- :exc:`~xml.dom.NoModificationAllowedErr`:

Raised if this declaration is readonly or a property is readonly.

- :exc:`~xml.dom.SyntaxErr`:

Raised if the specified CSS string value has a syntax error and

is unparsable.

Format::

variableset

: vardeclaration [ ';' S* vardeclaration ]*

;

vardeclaration

: varname ':' S* term

;

varname

: IDENT S*

;

expr

: [ VARCALL | term ] [ operator [ VARCALL | term ] ]*

;

"""

self._checkReadonly()

vardeclaration = Sequence(

PreDef.ident(),

PreDef.char(':', ':', toSeq=False, optional=True),

# PreDef.S(toSeq=False, optional=True),

Prod(

name='term',

match=lambda t, v: True,

toSeq=lambda t, tokens: (

'value',

PropertyValue(itertools.chain([t], tokens), parent=self),

),

),

)

prods = Sequence(

vardeclaration,

Sequence(

PreDef.S(optional=True),

PreDef.char(';', ';', toSeq=False, optional=True),

PreDef.S(optional=True),

vardeclaration,

minmax=lambda: (0, None),

),

PreDef.S(optional=True),

PreDef.char(';', ';', toSeq=False, optional=True),

)

# parse

wellformed, seq, store, notused = ProdParser().parse(

cssText, 'CSSVariableDeclaration', prods, emptyOk=True

)

if wellformed:

newseq = self._tempSeq()

newvars = {}

# seq contains only name: value pairs plus comments etc

nameitem = None

for item in seq:

if 'IDENT' == item.type:

nameitem = item

elif 'value' == item.type:

nname = normalize(nameitem.value)

if nname in newvars:

# replace var with same name

for i, it in enumerate(newseq):

if normalize(it.value[0]) == nname:

newseq.replace(

i,

(nameitem.value, item.value),

'var',

nameitem.line,

nameitem.col,

)

else:

# saved non normalized name for reserialization

newseq.append(

(nameitem.value, item.value),

'var',

nameitem.line,

nameitem.col,

)

# newseq.append((nameitem.value, item.value),

# 'var',

# nameitem.line, nameitem.col)

newvars[nname] = item.value

else:

newseq.appendItem(item)

self._setSeq(newseq)

self._vars = newvars

self.wellformed = True

cssText = property(

_getCssText,

_setCssText,

doc="(DOM) A parsable textual representation of the declaration "

"block excluding the surrounding curly braces.",

)

def _setParentRule(self, parentRule):

self._parentRule = parentRule

parentRule = property(

lambda self: self._parentRule,

_setParentRule,

doc="(DOM) The CSS rule that contains this"

" declaration block or None if this block"

" is not attached to a CSSRule.",

)

def getVariableValue(self, variableName):

"""Used to retrieve the value of a variable if it has been explicitly

set within this variable declaration block.

:param variableName:

The name of the variable.

:returns:

the value of the variable if it has been explicitly set in this

variable declaration block. Returns the empty string if the

variable has not been set.

"""

try:

return self._vars[normalize(variableName)].cssText

except KeyError:

return ''

def removeVariable(self, variableName):

"""Used to remove a variable if it has been explicitly set within this

variable declaration block.

:param variableName:

The name of the variable.

:returns:

the value of the variable if it has been explicitly set for this

variable declaration block. Returns the empty string if the

variable has not been set.

:exceptions:

- :exc:`~xml.dom.NoModificationAllowedErr`:

Raised if this declaration is readonly is readonly.

"""

normalname = variableName

try:

r = self._vars[normalname]

except KeyError:

return ''

else:

self.seq._readonly = False

if normalname in self._vars:

for i, x in enumerate(self.seq):

if x.value[0] == variableName:

del self.seq[i]

self.seq._readonly = True

del self._vars[normalname]

return r.cssText

def setVariable(self, variableName, value):

"""Used to set a variable value within this variable declaration block.

:param variableName:

The name of the CSS variable.

:param value:

The new value of the variable, may also be a PropertyValue object.

:exceptions:

- :exc:`~xml.dom.SyntaxErr`:

Raised if the specified value has a syntax error and is

unparsable.

- :exc:`~xml.dom.NoModificationAllowedErr`:

Raised if this declaration is readonly or the property is

readonly.

"""

self._checkReadonly()

# check name

wellformed, seq, store, unused = ProdParser().parse(

normalize(variableName), 'variableName', Sequence(PreDef.ident())

)

if not wellformed:

self._log.error(f'Invalid variableName: {variableName!r}: {value!r}')

else:

# check value

if isinstance(value, PropertyValue):

v = value

else:

v = PropertyValue(cssText=value, parent=self)

if not v.wellformed:

self._log.error(f'Invalid variable value: {variableName!r}: {value!r}')

else:

# update seq

self.seq._readonly = False

variableName = normalize(variableName)

if variableName in self._vars:

for i, x in enumerate(self.seq):

if x.value[0] == variableName:

self.seq.replace(

i, [variableName, v], x.type, x.line, x.col

)

break

else:

self.seq.append([variableName, v], 'var')

self.seq._readonly = True

self._vars[variableName] = v

def item(self, index):

"""Used to retrieve the variables that have been explicitly set in

this variable declaration block. The order of the variables

retrieved using this method does not have to be the order in which

they were set. This method can be used to iterate over all variables

in this variable declaration block.

:param index:

of the variable name to retrieve, negative values behave like

negative indexes on Python lists, so -1 is the last element

:returns:

The name of the variable at this ordinal position. The empty

string if no variable exists at this position.

"""

try:

return list(self.keys())[index]

except IndexError:

return ''

length = property(

lambda self: len(self._vars),

doc="The number of variables that have been explicitly set in this"

" variable declaration block. The range of valid indices is 0"

" to length-1 inclusive.",

)